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United States Patent |
5,063,716
|
Raikhlin
|
November 12, 1991
|
Hoisting apparatus
Abstract
The hoisting apparatus is comprised of a mast (1) consisting of four
vertical rods (2, 2', 3,3') two of which have internal spaces
accommodating strength members. The rods (3, 3') with strength members and
other rods (2, 2') are arranged in pairs symmetrically to the vertical
axis (5) of symmetry of the mast (1) and the cargo suspension (10) is,
essentially, a rectangular frame enveloping the mast (1) and formed by two
parallel beams (11, 11') each rigidly connected in its center with the
corresponding bracket (9, 9'), and by two parallel rocker arms (12, 12')
whose ends are articulated to the ends of the beams (11, 11').
Inventors:
|
Raikhlin; Mark M. (Volgo-gradsky prospekt, 9, kv. 89, Moscow, SU)
|
Appl. No.:
|
582914 |
Filed:
|
October 15, 1990 |
PCT Filed:
|
February 17, 1989
|
PCT NO:
|
PCT/SU/89/0004
|
371 Date:
|
October 15, 1990
|
102(e) Date:
|
October 15, 1990
|
PCT PUB.NO.:
|
WO90/09334 |
PCT PUB. Date:
|
August 23, 1990 |
Current U.S. Class: |
52/114; 52/115; 52/167.1 |
Intern'l Class: |
E04H 012/18 |
Field of Search: |
52/111,114,116,117,121
|
References Cited
U.S. Patent Documents
468186 | Feb., 1892 | Beardsley | 52/167.
|
2739673 | Mar., 1956 | Foster | 52/111.
|
3954157 | May., 1976 | Atkey.
| |
Foreign Patent Documents |
417082 | Feb., 1981 | SE.
| |
1051025 | Oct., 1983 | SU.
| |
2053150 | Feb., 1981 | GB.
| |
Primary Examiner: Scherbel; David A.
Assistant Examiner: Wood; Wynn
Attorney, Agent or Firm: Fleit, Jacobson, Cohn, Price, Holman & Stern
Claims
I claim:
1. A hoisting apparatus in the form of a mast (1) consisting of four
vertical rods (2,2', 3,3') interconnected by a lattice (4) two of said
rods having internal spaces accommodating strength members (8,8') capable
of moving along the rods (3,3'), one of said members in each rod (3,3')
being connected with the corresponding brackets (9,9') which, in turn, are
fastened to the cargo suspension (10) characterized in that the rods
(3,3') with the strength members (8,8') and the rods (2,2') are arranged
in pairs, symmetrically to the vertical axis (5) of symmetry of the mast
(1) and the cargo suspension (10) is, essentially, a rectangular frame
enveloping the mast (1) and formed by two parallel beams (11,11'), each
rigidly connected in its center with the corresponding bracket (9,9'), and
by two parallel rocker arms (12,12') whose ends are articulated to the
ends of the beams (11,11').
Description
TECHNICAL FIELD
The present invention relates to hoisting-and-conveying equipment and, more
particularly, it relates to a hoisting apparatus.
BACKGROUND OF THE INVENTION
Known in the prior art is a hoisting apparatus realized in the form of a
mast consisting of a vertical hollow rod secured in the base, the inside
space of said rod accommodating strength members which are capable of
moving along the rod. Said members are moved in two parallel rows--over
the load carrying branch and the accumulating branch, the strength members
being transferred from one branch to another by an operating mechanism
installed in the rod base. The strength member nearest to the rod top
supports a bracket connected to a cargo suspension (SU, A, 1051025).
The load capacity of the known apparatus is limited due to asymmetric
application of load to the mast since the bracket carrying the cargo
suspension and taking the load of the cargo moves over a guide located at
one side of the rod, i.e. the load acts eccentrically relative to the
vertical central axis of symmetry of the mast which restricts the load
capacity of the apparatus.
There is another known cargo-hoisting apparatus in the form of a mast
formed by four vertical rods interconnected by a lattice, two of said rods
having spaces with strength members movably installed inside. One of
strength members in each rod is connected with one of the cargo suspension
brackets (SE, C, 417082). In this apparatus two rods with strength members
are installed in one side plane of the mast while the two other rods, in
the side surface of the mast which is parallel to the first surface; in
this case the cargo suspension is, essentially, a beam whose ends are
rigidly secured to the brackets and which has a cargo grip in the centre.
The hoisting apparatus is noted for a higher load capacity, since the load
is distributed between two load-carrying branches in both rods with
strength members. However, for reliable functioning of the known apparatus
the strength members in the spaces of both rods should move in strict
synchronism. If synchronism is disturbed, the cargo suspension may be
cocked and jammed. Cocking of the cargo suspension also brings about heavy
wear of parts at points where brackets interact with the strength members
due to forces of friction. It should be noted that this hoisting apparatus
is also characterized by asymmetrical effect of the load on the mast
because the cargo suspension moves along one side of the mast so that the
weight of the hoisted cargo acts eccentrically relative to the vertical
central axis of symmetry of the mast.
SUMMARY OF THE INVENTION
The main object of the invention is to provide a hoisting apparatus with
such a design of the mast and cargo suspension which would ensure
application of load along the axis of symmetry of the mast during hoisting
of the load, and uniform distribution of this load among all the rods of
the mast and which would rule out the possibility of jamming of the moving
cargo suspension even during asynchronous movement of the strength members
in the rods.
This problem is solved by providing a hoisting apparatus in the form of a
mast consisting of four vertical rods interconnected by a lattice, two of
said rods having internal spaces accommodating strength members installed
therein with a provision for moving along the rods, one of said members in
each rod being connected with the corresponding bracket which, in turn, is
fastened to the cargo suspension in which, according to the invention, two
rods with strength members and two other rods are arranged in pairs
symmetrically to the vertical axis symmetry of the mast and the cargo
suspension is constituted by a rectangular frame fitting around the mast
and formed by two parallel beams, rigidly connected, each, by its central
part with the corresponding bracket, and by two parallel rocker arms whose
ends are articulated to the ends of the beams.
In the hoisting apparatus realized according to the present invention the
weight of the lifted cargo acts precisely along the central vertical axis
of symmetry of the mast and is distributed uniformaly among all the four
rods thus enabling the load capacity of the apparatus to be raised
considerably without increasing the power of the drive and stiffness of
construction. Asynchronous movement of the strength members in the mast
rods only changes the inclination angle of the frame (cargo suspension)
plane to the axis of symmetry of the mast while the load acting on the
rods stays constant and depends on the weight of the cargo being hoisted.
This precludes the possibility of cargo suspension jamming in case of
asynchronous movement of strength members in the mast rods.
BRIEF DESCRIPTION OF THE DRAWINGS
Now the invention will be described by way of example with reference to the
accompanying drawings, in which:
FIG. 1 is a general view of the hoisting apparatus according to the
invention;
FIG. 2 is a section taken along line II--II in FIG. 1, enlarged;
FIG. 3 is a fragment A in FIG. 1, partly cut away, enlarged.
BEST MODE FOR CARRYING OUT THE INVENTION
The hoisting apparatus illustrated in FIGS. 1,2,3 comprises a mast 1 formed
by four vertical rods 2,2' and 3,3'. The rods 2,2', 3,3' are
interconnected by a lattice 4.
The rods 2,2' and 3,3' are arranged in pairs symmetrically to the central
vertical axis 5 of symmetry of the mast 1. The rods 3 and 3' are hollow
and the internal space of each rod has two load-carrying and accummulating
branches 6,6' and 7,7' respectively. Accommodated in branches 6,6' and
7,7' are strength members 8,8' capable of reciprocating along the rods
3,3' and of moving from one branch, e.g. 6,6' into the other branch, e.g.
7,7'.
The strength members 8,8' hearest to the top of the mast 1, located in the
load-carrying branches 6,6' are connected with brackets 9,9' which, in
turn, are fastened to the cargo suspension 10.
The cargo suspension 10 is a rectangular frame enveloping the mast 1 over
the perimeter. The frame 10 is formed by two parallel beams 11,11', each
rigidly connected in its central part with the corresponding bracket 9,9',
and by two parallel rocker arms 12 and 12' whose ends are articulated by
shackles 13 to the ends of the beams 11,11'.
The mechanism 14,14' for operating the strength members 8,8' is located in
the lower part of the mast 1 under each of the rods 3 and 3'. Each
mechanism 14,14' has a drive, (e.g. hydraulic) of its own (not shown in
the drawing). The strength member operating mechanisms 14,14' transfer the
strength members 8 and 8' from the accumulating branches 7 and 7' into the
load-carrying branches 6 and 6', and back.
The mechanism 14 and 14' are housed in a common casing 15 on which the mast
1 is installed.
In addition, the casing 15 with the mast 1 is mounted on a transport
vehicle 16, though it may be installed in a stationary way too.
the hoisting apparatus functions as follows.
As the operating mechanisms 14 and 14' are switched on for lifting motion
the strength members 8 and 8' start moving from the accumulating branches
7 and 7' into load-carrying branches 6 and 6'; the branckets 9 and 9'0
connected with the strength members 8,8' nearest to the top of the mast 1
start moving upward along the load-carrying branches 6 and 6' and,
consequently, the cargo suspension 10 with the attached cargo (not shown
in the drawing) starts going up along the mast 1.
Inasmuch as the operating mechanisms 14,14' cannot work in absolute
synchronism, the brackets 9 and 9' may move out of synchronism, i.e. the
bracket 9, for example, may lag behind the bracket 9'; hence, the beams 11
and 11' of the cargo suspension 10 rigidly connected with said brackets
will also move out of synchronism.
The resultant cocking of the rocker arms 12,12' articulated with beams
11,11' does not impose additional loads on the rods 3 and, consequently,
on the entire structure of the mast 1 because the arm of the force of the
handled load applied to the rods 3 and 3' stays unchanged in spite of
cocking of the rocker arms 12 and 12'.
Besides, due to symmetrical arrangement of rods 3 and 3' relative to the
central axis 5 of symmetry of the mast 1, said rods functioning as guides
for the moving suspension 10, the forces arising in the mast 1 under the
weight of the hoisted cargo are distributed symmetrically relative to the
vertical axis 5 of the mast 1 among all the rods 2,2' and 3,3' which rules
out probable bending moments in the mast 1 which, in turn, permits
reducing its mass at the same load capacity.
In case of a very heavy cargo the provision of two guides, i.e. two rods
with strength members and two operating mechanisms, permits dispensing
with the drive of a high unit power which also contributes to reducing the
cost of the hoisting apparatus according to the invention.
INDUSTRIAL APPLICABILITY
The hoisting apparatus can be employed in construction and erection work,
when building industrial and public service, objects, engineering
structures, installation of technological equipment also in reconstruction
and major rebuilding of industrial objects.
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